JP2003134115A - Communication equipment and address setting method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set an inherent address on a communication network by avoiding address overlapping. SOLUTION: A memory part 4 of first start communication equipment is provided with an address management table 42 for unitarily managing the use state of each subaddress, and an address managing means 3C of the first start communication equipment transmits an address management message showing an unused subaddress acquired from the address management table 42 to the communication network 1. Address setting means 3D of respective subsequent start communication equipment set an unused subaddress as a self- subaddress on the basis of the address management message, and notify the first start communication equipment of the subaddress with an address return message, and the address managing means 3C of the first start communication equipment makes the use state of the subaddress notified with the address return message to be in use in the address management table 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device and an address setting method thereof, and more particularly to a communication device for performing data communication with another communication device using an address unique to each communication device and an address setting method thereof. is there.

[0002]

2. Description of the Related Art Generally, when performing data communication between a plurality of communication devices connected to a communication network, a data communication partner is set using a unique address preset on each communication device on the communication network. It is designated. For example, in Ethernet (registered trademark), which is a typical communication network, a MAC (Media Access Control) address is used as the address.

Conventionally, in such a communication device, in order to avoid address duplication with other communication devices connected to the communication network, at least a part of the address can be arbitrarily changed for each communication device. ing. For example,
As shown in FIG. 9A, the communication device 91 is provided with a DIP switch 92, and by setting the DIP switch 92 to be switched, avoiding address duplication, or FIG. 9B.
As shown in FIG. 3, the communication device 93 and the PC (personal computer) 95 are connected by a communication cable 94, and the PC 95 connects the communication device 9 to the communication device 9.
The address duplication was avoided by changing and setting the address of No. 3.

[0004]

However, in such a conventional communication device, a user's manual work is required when setting an address, and when setting an address for a plurality of communication devices, a heavy work load is required. There was a problem that Also, there is a possibility that an address setting error will occur manually, and if the error is overlooked and data communication is started with address duplication existing,
Not only the communication efficiency may decrease, but also the communication device may malfunction, which may have a great influence on the system that controls using the communication network. The present invention is intended to solve such a problem, and an object of the present invention is to provide a communication device capable of avoiding address duplication and automatically setting a unique address on a communication network, and an address setting method thereof.

[0005]

In order to achieve such an object, a communication device according to the present invention is connected to a communication network to perform data communication with other communication devices using respective unique addresses. , A communication device that sets its own sub-address that composes all or part of its own address after it is started by turning on the power, and is the one of the communication devices connected to the communication network when starting by turning on the power. A startup processing unit that determines whether or not the communication device is the earliest activated communication device, and operates if the communication device is determined to be the earliest activated communication device by the activation processing unit. An address manager that sends an address management message that notifies unused subaddresses to other subsequent startup communication devices that have started after the startup communication device. Means and the activation processing means operate when the communication device is determined to be a subsequent activation communication device, and the unused subaddress notified by the address management message from the earliest activation communication device is used for the subsequent activation communication. And an address setting means for setting the device as its own sub-address.

As a configuration for confirming the usage status of the sub-address, after the address setting means sets the own sub-address, an address reply message including the own sub-address is returned to the earliest starting communication device, and the address managing means starts the subsequent operation. It may be possible to confirm that the sub address is in use in response to an address reply message from the communication device.

In order to avoid duplicate setting of subaddresses,
In the address management means, if the sub-address notified by the address reply message from the subsequent activation communication device is already used by another communication device, the sub-address already set to the subsequent activation communication device having the sub-address is set. Sending a reset message for initialization and resetting, and the address setting means initializes its own subaddress according to the reset message from the earliest starting communication device and sets its own subaddress by a new address management message. May be confirmed.

Further, the communication device address setting method according to the present invention is connected to a communication network to perform data communication with other communication devices by using respective unique addresses, and after starting by turning on the power, the own address is set. Is a method for setting the address of a communication device that sets all or part of its own sub-address, which is the first activated communication device that is activated first among the communication devices connected to the communication network. An address management message that notifies an unused sub-address is sent to other subsequent activation communication devices that have been activated following the activation communication device, and the subsequent activation communication device is notified by the address management message from the earliest activation communication device. The unused subaddress is set as the own subaddress of the subsequent activation communication device.

As a method of confirming the usage state of the sub-address, after setting the own sub-address in the subsequent activation communication device, an address reply message including the own sub-address is returned to the earliest activation communication device, and the first activation communication device The sub-address may be confirmed to be in use in response to an address reply message from the subsequent activation communication device.

In order to avoid duplication of subaddresses,
In the earliest startup communication device, if the sub-address notified by the address reply message from the subsequent startup communication device is already used by another communication device, it is already set to the subsequent startup communication device with the sub-address. A reset message for initializing and resetting the subaddress is sent, and the subsequent startup communication device initializes its own subaddress in response to the reset message from the earliest startup communication device and sets its own subaddress by a new address management message. You may confirm that it does.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a communication device and a communication network according to an embodiment of the present invention. Communication equipment 1A, 1B, 1C, ...
Are devices that are respectively connected to the communication network 1 and perform data communication with each other via the communication network 1. These communication devices 1A, 1B, 1C, ...
It has the same configuration and includes a communication I / F unit 2, a control unit 3, and a memory unit 4, respectively.

The communication I / F unit 2 is an interface circuit unit that performs data communication by transmitting and receiving signals to and from other communication devices via the communication network 1. The control unit 3 includes a microprocessor such as a CPU and its peripheral circuits, and is a control circuit unit that controls the communication device by executing a predetermined program. The control unit 3 includes a message transmitting / receiving unit 3A and a start processing unit 3 as functional units realized by cooperation of the above hardware resources and software consisting of programs.
B, address management means 3C and address setting means 3D
Is provided.

In the message transmitting / receiving means 3A, communication I /
Messages are exchanged with other communication devices via the F unit 2. In particular, among the messages flowing on the communication network 1, only the message in which the address or the specific address of the communication device is set as the destination address is received. Here, in addition to a message for exchanging desired data with another communication device, an address management setting message for managing and setting the address of the communication device and another communication device is also handled.

When the activation processing means 3B is activated by turning on the power, it determines whether or not the communication equipment connected to the communication network 1 is the earliest activated communication equipment. The address managing means 3C operates when the communication processing device 3B determines that the communication device is the earliest activation communication device, and does not notify the other subsequent activation communication device activated after the communication device. The sub-address of the subsequent activation communication device is managed by transmitting an address management message that notifies the sub-address of use.

The address setting means 3D is a start processing means 3
It operates when B determines that the communication device is the subsequent activation communication device, and uses the unused subaddress notified by the address management message from the earliest activation communication device as its own subaddress of the subsequent activation communication device. Set. The memory unit 4 is a memory circuit for storing information necessary for the processing operation of the control unit 3. Here, the address assigned to the communication device, that is, its own sub-address 41
Is memorized. Further, if necessary, an address management table 42 for centrally managing the usage status of addresses used in each communication device is also stored.

In the following, a case will be described in which Ethernet, which is a typical communication network, is taken as an example, and a MAC (Media Access Control) address used in this Ethernet is set in each communication device. FIG. 2 shows a configuration diagram of the MAC address. The MAC address has a 6-byte length (48-bit length), and the upper 5 bytes (byte
For 6 to byte 2/40 bit length), a unique address previously assigned to the maker of the communication device and the product, that is, the device maker unique address 51 is used. Then, the remaining lower 1 byte (byte 1/8
(Bit length) is used as an address or subaddress 52 that can be arbitrarily set by the user.

Therefore, when such a MAC address configuration is used, if the makers of the respective communication devices are different, the device manufacturer's unique address 51 is naturally different, so that no address duplication occurs. However, in reality, there are many cases where a plurality of communication devices of the same model are used by the same manufacturer, and in such a case, it is necessary to adjust the sub-address 52 between these communication devices.

In the present embodiment, this subaddress 52
Is automatically set in each communication device without duplication. In particular, in the case of a MAC address, the sub address 52
Has a 1-byte length, 256 types of subaddresses can be set. However, for the address value "255",
It is reserved by the system as a common address used for broadcast type messages, and the address range that can be actually used for automatic setting is "0" to "254".

Further, in this embodiment, when setting the sub-address, the sub-address is set in each communication device by utilizing the power-on sequence of each communication device, that is, the activation sequence. Then, it is assumed that the communication device that is activated first manages the usage states of all subaddresses, and the address management table 42 described above is stored and managed in the memory unit 4 as a management table for that purpose. Therefore, the address management table 42 is not necessary for all communication devices, but may be provided for the earliest activated communication device activated first.

FIG. 3 shows a configuration example of the address management table. Here, a usage status flag is stored for each sub-address, and when the usage status flag is "1", it indicates that the sub-address is used by any communication device, and the usage status flag is "0". In the case of, it indicates that the sub address is not used in any communication device.

Next, the operation of the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing an activation process at power-on as an operation of the communication device according to the present invention. When the communication device is powered on, the activation processing means 3B of the control unit 3 starts the activation processing shown in FIG. First, the message transmitting / receiving unit 3A waits for a message from the communication network 1 for a predetermined period (step 10).
0), It is confirmed whether or not there is a communication device operating on the communication network 1. Note that the message waiting to be received may be all messages or only specific messages, for example, only the address management message from the earliest activation communication device.

Here, if the message is not received (step 101: YES), the communication network 1
Since it is determined that there is no other communication device in operation and the communication device is the earliest activated communication device activated first, the address management means 3C for managing the address of the other communication device. Is started (step 102), and a series of start-up processing is ended. If any message is received (step 101: NO), it is determined that there is a communication device in operation on the communication network 1, and the own subaddress is set based on the address management process by the earliest activation communication device. The address setting means 3D is activated (step 103), and a series of activation processing is terminated.

Next, the address management processing in the earliest activation communication device will be described with reference to FIG. FIG. 5 is a flowchart showing the address management process. In the address management means 3C of the communication device which is the earliest activated communication device, first, the sub-address “0” is selected as the self-sub-address, the self-sub-address 41 is registered in the memory unit 4, and the sub-address “ The use state flag of "0" is set to "1", and the fact that the sub address "0" is in use is registered (step 110).

Then, an address management message for managing the address of another communication device which is powered on and started after the earliest starting communication device is transmitted to the communication network 1 via the message transmitting / receiving means 3A (step 111). FIG. 6 shows a configuration example of the address management message. The configuration of the address management message 6 is the same as the configuration of a general message used in Ethernet as a whole, and detailed description of each unit will be omitted. In the address management message 6 used in the present embodiment, in particular, the broadcast form subaddress “255” is used as the subaddress of the destination MAC address 61, and the subaddress “0” set in step 110 is set as the subaddress of the source MAC address 62. Is used.

Further, in the address management message 6, the sub-address use state information 63 is stored in order to notify the other communication device which performs the address setting process of the own device, that is, the subsequent activated communication device, in order to notify the sub-address use state. There is. The sub-address usage status information 63 is composed of usage status flags of each sub-address managed by the address management table 42. The subsequent activation communication device refers to this sub-address use state information 63 and selects an unused sub-address as its own sub-address.

Address management means 3C of the earliest starting communication device
Then, after transmitting such an address management message on the communication network 1, it waits for reception of an address reply message from another communication device for a predetermined period (step 112). FIG. 7 shows a configuration example of the address reply message. The address reply message 7 is a message for notifying the earliest starting communication device of its own sub-address set by receiving the address management message 6 by another communication device.

The structure of the address reply message 7 is the same as the structure of a general message used in the Ethernet as a whole, and detailed description of each part is omitted. In the address reply message 7 used in the present embodiment, in particular, as the transmission destination MAC address 71, the transmission source address of the address management message 6 (sub address = “0”)
Is used, and the own sub-address set in the communication device is used as the sub-address of the source MAC address 71. It should be noted that the address reply message 7 itself does not store valid information, but stores temporary dummy data 73.

When such an address reply message is received (step 113: YES), the address management means 3C of the earliest starting communication device extracts the sender subaddress from the sender MAC address of the address reply message. The address management table 42 is collated (step 114), and the use state of the transmission source sub-address is confirmed (step 115). Here, if the transmission source sub-address is in an unused state (step 115: YE
S) In the address management table 42, the use status flag of the transmission source subaddress is set to "1" to register that it is in use (step 116). Then, returning to step 111, a new address management message in which the updated contents of the address management table 42 are reflected is transmitted, and the address management process for another newly activated communication device is continued.

On the other hand, if the transmission source sub-address is in use (step 115: NO), it is determined that an address duplication setting has occurred, and each succeeding starting communication device having that sub-address has its own address. A reset message is transmitted over the communication network 1 to initialize and reset the subaddress (step 116), and the process returns to step 111. Note that the reset message has the same configuration as the address reply message 7 (FIG. 7), and detailed description thereof will be omitted. Note that instead of the dummy data 73, message type information indicating that the message is a reset message is stored.

Each of the subsequent activation communication devices that have received this reset message waits for a random time, and then
The address setting process using the new address management message is executed again. The purpose of waiting for the random time is to shift the restart timing of the address setting processing of each one, so that reoccurrence of duplicate address setting can be reliably prevented. Also, step 1
Even when the address reply message is not received in step 13 (step 113: NO), the process returns to step 111, a new address management message is transmitted, and the address management process for the newly activated other communication device is continued. .

Next, with reference to FIG. 8, the address setting processing in the subsequent activation communication device which is activated after being powered on after the earliest activation communication device will be described. FIG. 8 is a flowchart showing the address setting process. The address setting means 3D of the subsequent activation communication device first waits for an address management message for a predetermined period (step 12).
0) When the address management message from the earliest activation communication device is received (step 121: YES), the sub-address use state information 63 (see FIG. 6) of the address management message 6 is acquired.

Then, the subaddress use state information 6
3 to an unused subaddress, for example, the youngest unused subaddress in order (step 12
2) Then, it is registered in the memory section 4 as its own subaddress 41 (step 123). After that, in order to notify the earliest activation communication device of the set own sub-address, the address reply message 7 shown in FIG. 7 is transmitted to the communication network 1 (step 124), and a series of address setting processing is ended. As a result, the address return message is received by the earliest activation communication device, and the address is managed so that the subaddress is not used again.

As described above, in the present embodiment, of the plurality of communication devices connected to the communication network 1, the address management for centrally managing the usage state of each sub-address in the memory unit 4 of the communication device which is activated first. Provide a table 42,
In the address management means 3C of the earliest starting communication device, after setting its own sub-address, the address management table 42 is set.
The address management message indicating the unused sub-address acquired from the communication network 1 is transmitted to the communication network 1. Then, the address setting means 3D of each subsequent activation communication device selects an unused subaddress based on the address management message and sets it as its own subaddress, and notifies the earliest activation communication device of the set subaddress by an address reply message. In the address management means 3C of the earliest start-up communication device, the use status of the sub-address notified by the address reply message is set to be in use in the address management table 42.

Therefore, for each communication device, it is possible to avoid address duplication and set a unique address on the communication network. This allows you to
There is no need for the user to manually set the address of each communication device, and the work load required for address setting is almost eliminated. When setting addresses for multiple communication devices, the work load is extremely large. It will be reduced.
Furthermore, address setting errors due to manual work are eliminated, communication efficiency is not reduced and communication devices do not malfunction due to address duplication, and there is no effect on the system that controls using the communication network.

Also, in Ethernet, the transmission order of messages between a plurality of communication devices is CSMA /
CD (Carrier Sense Multiple Access with Collision
Detection: Carrier-sensitive multiple access / collision detection) method is used. This CSMA / CD system monitors a carrier detection signal on a communication line, transmits data when other communication equipment is not transmitting, delays data transmission when transmitting, and detects the carrier detection signal. It is a method of transmitting data when it is no longer available. Further, when a data collision occurs, a jam signal (interfering signal) is transmitted and then retransmitted after a waiting time corresponding to a random number. Therefore, an address reply message is rarely transmitted from a plurality of subsequently activated communication devices at the same time.

However, there is a possibility that a plurality of subsequent activation communication devices that are powered on and activated at almost the same time will perform address setting processing in parallel based on the same address management message. In the present embodiment, assuming such a case, the address management means 3 of the earliest starting communication device 3
In C, when the use of the same subaddress is notified from a plurality of subsequent activation communication devices, a reset message instructing initialization of the subaddress is transmitted to the subsequent activation communication device having the subaddress, and these subsequent activation communication devices are , In response to the reception of this reset message, the own sub-address that has been set once is initialized, and after each person waits for a random time, the address setting process by the new address management message is executed again. Can be completely avoided.

In the above description, when the unused subaddress is notified by the address management message, the subaddress use state information 63 including the use state flag provided for each subaddress is transmitted as an example. However, the present invention is not limited to this. It is not something that will be done. For example, in the address management means 3C of the earliest activation communication device, the address management table 42
It is also possible to select an unused sub-address from, for example, the youngest unused sub-address in order, and notify the selected sub-address by an address management message.

[0038]

As described above, according to the present invention, the earliest activated communication equipment that is activated first among the communication equipments connected to the communication network is activated subsequent to the earliest activated communication equipment. Sends an address management message that notifies an unused sub-address to another subsequent activation communication device, and the subsequent activation communication device activates the unused sub-address notified by the address management message from the earliest activation communication device. Since it is set as its own sub-address of the communication device, it is possible to avoid address duplication and set a unique address on the communication network for each communication device. This eliminates the need for the user to manually set the address of each communication device, as in the past.
The work load required for address setting is almost eliminated, and when setting addresses for a plurality of communication devices, the work load is significantly reduced. further,
The address setting error caused by the manual work is eliminated, the communication efficiency is not deteriorated due to the address duplication, and the malfunction of the communication device does not occur, and there is no influence on the control system using the communication network.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a communication device and a communication network according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a MAC address.

FIG. 3 is a configuration example of an address management table.

FIG. 4 is a flowchart showing a startup process in a communication device.

FIG. 5 is a flowchart showing an address management process in the earliest activation communication device.

FIG. 6 is a configuration example of an address management message.

FIG. 7 is a configuration example of an address reply message.

FIG. 8 is a flowchart showing an address setting process in a subsequent activation communication device.

FIG. 9 is an explanatory diagram showing a conventional address setting method.

[Explanation of symbols]

1 ... communication network, 1A, 1B, 1C ... communication equipment,
2 ... communication I / F section, 3 ... control section, 3A ... message, 3
B ... Startup processing means, 3C ... Address management means, 3D ... Address setting means, 4 ... Memory part, 41 ... Own subaddress, 42 ... Address management table, 51 ... Device manufacturer unique address, 52 ... Subaddress, 6 ... Address management message , 61 ... Destination MAC address, 62 ... Source MAC address, 63 ... Sub-address use status information, 7
... address reply message, 71 ... destination MAC address, 72 ... source MAC address, 73 ... dummy data.

Claims (6)

[Claims] 1. A self-sub address that is connected to a communication network and performs data communication with another communication device by using a unique address of each, and after starting by power-on, forms all or part of its own address A communication device to be set, which, when activated upon power-on, determines whether or not the communication device connected to the communication network is the communication device that has been activated first, This startup processing unit operates when it is determined that the communication device is the earliest startup communication device, and sends an unused sub-address to another subsequent startup communication device that has started after the earliest startup communication device. Address management means for transmitting an address management message for notifying that the communication device is a subsequent activation communication device by the activation processing means. And an address setting unit that operates when it is determined that the unused subaddress notified by the address management message from the earliest activation communication device is set as the own subaddress of the subsequent activation communication device. And communication equipment. 2. The communication device according to claim 1, wherein the address setting means, after setting the own subaddress, returns an address reply message including the own subaddress to the earliest starting communication device, and manages the address. The communication device is characterized in that the means confirms that the sub-address is in use in response to an address reply message from the subsequent activation communication device. 3. The communication device according to claim 2, wherein when the sub-address notified by the address reply message from the subsequent activation communication device is already used in another communication device, the address management means Subsequent startup communication device having a sub-address, sending a reset message for initializing and resetting the already set sub-address, the address setting means, in response to the reset message from the earliest startup communication device, A communication device, characterized in that the own sub-address is initialized and it is confirmed that the own sub-address is set by a new address management message. 4. A sub-address, which is connected to a communication network and performs data communication with another communication device by using a unique address of each, and which has all or part of its own address after being activated by power-on. A method for setting an address of a communication device to be set, wherein, from among the communication devices connected to the communication network, the first activated communication device that is activated first and the other activated after the earliest activated communication device are activated. An address management message for notifying an unused sub-address is transmitted to the subsequent activation communication device, and the unused sub-address notified by the address management message from the earliest activation communication device is transmitted to the subsequent activation communication device. A method for setting an address of a communication device, which is characterized in that the device is set as its own sub-address. 5. The communication device address setting method according to claim 4, wherein the subsequent activation communication device sets the self subaddress, and then returns an address reply message including the self subaddress to the earliest activation communication device. Then, the address setting method of the communication device, wherein the earliest startup communication device confirms that the sub-address is in use in response to an address reply message from the subsequent startup communication device. 6. The communication device address setting method according to claim 5, wherein the sub-address notified by the address reply message from the subsequent activation communication device is already used by another communication device in the earliest activation communication device. If it is, a reset message for initializing and resetting the already set sub address is transmitted to the subsequent activation communication device having the sub address, and the subsequent activation communication device sends the reset message from the earliest activation communication device. The address setting method of the communication device, wherein it is confirmed that the own sub-address is initialized and the own sub-address is set by a new address management message in response to the reset message.